Interiors

Goodrich Corporation

3414 South Fifth Street

Phoenix, Arizona 85040-1169

Tel: (602) 243-2200

Fax: (602) 243-2300

LETTER OF TRANSMITTAL

TO: Holders of Goodrich Service Bulletin 25-349, Original Issue.

SUBJECT: Goodrich Service Bulletin 25-349, Revision 1, Dated Jan 11/10.

REASON: Revised Part Number Identification Table 4 to clarify the use of Piston Plug P/N’s on 

Regulator Valves.

ACTION: Replace Goodrich Service Bulletin 25-349, Original Issue with Revision 1, 

Dated Jan 11/10.

HIGHLIGHTS

Revised Part Number Identification Table 4 to clarify the use of Piston Plug P/N’s on 

Regulator Valves.

Previous Issues:

Original - Sep 15/04

PAGE CHANGE

1 Added Data

2 Added Data

6 Added Data

8 Added Data

PAGE CHANGE

(END)

INTERIORS

PHOENIX, ARIZONA 85040

SERVICE BULLETIN

ATA SYSTEM: 25

25-349

Page 1 of 8

Orig. - Sep 15/04

Revision 1 - Jan 11/10

Subject: Equipment/Furnishings - Evacuation Systems -

TRANSMITTAL OF TECHNICAL DATA (EAR): 

THESE COMMODITIES, TECHNOLOGY OR SOFTWARE ARE CONTROLLED BY THE U.S. EXPORT ADMINISTRATION REGULATIONS

(EAR). DIVERSION CONTRARY TO U.S. LAW IS PROHIBITED. 

LICENSE EXCEPTION: NLR 

ECCN: 9E991

1. Planning Information

A. Effectivity

(1) Equipment - Boeing 737NG and MD-80/MD-90 emergency evacuation slides manufactured by 

Aircraft Interior Products, Goodrich Corporation, and its predecessors, as listed in Table 1, 

below, are affected by this Service Bulletin.

NOTE: Revision 1 to this Service Bulletin does not change the technical content of this 

action. Units modified under the previous issue of this Service Bulletin do not 

require additional modification. However, for regulator valves used on B737 slides 

P/N 5A3086-301, 5A3088-301, and 5A3307-301 only, an additional check at next 

unit overhaul may be required. Refer to the Note following paragraph 1.A.(2) for 

information applicable to those units only. 

Table 1. Unit Effectivity 

NOMENCLATURE EVACUATION SYSTEM P/N AFFECTED UNIT S/N

Slide, Fwd Door, LH/RH

MD-80/MD-90

100504-201, -203 and -205 D9F001 thru D9F257

Slide, Aft Service Door

MD-80/MD-90

100505-201 D9A001 thru D9A122

Slide, Tailcone

MD-80/MD-90

100506-201 and -203 D9T001 thru D9T128

Ream Vespel Piston Inner Diameter to Prevent 

Regulator Valve Hangfire
Goodrich

SERVICE BULLETIN

25-349

Page 2 of 8

Orig. - Sep 15/04

Revision 1 - Jan 11/10

THIS DOCUMENT SUBJECT TO THE CONTROLS AND RESTRICTIONS ON THE FIRST PAGE. 

(2) Action - Ream the inner diameter (ID) of the Vespel piston to prevent hangfire of the regulator 

valve and loss of evacuation system functionality.

NOTE: For regulator valve P/N’s 4A3865-4 and 4A3865-5 used on B737 slide P/N’s 

5A3086-301, 5A3088-301, and 5A3307-301 only, if the SB 25-349 action was 

accomplished by the optional action of replacing the “single piece” Vespel piston 

P/N 3A3566-1 with the “two piece” Vespel piston P/N 3A3832-2, at the next unit 

overhaul verify that piston plug P/N 300382-1 is used.

B. Reason

(1) Description - Regulator valves on certain Goodrich slide/rafts have not functioned (hangfired) 

during scheduled reliability deployments or during flat fire testing in the workshop. A hangfire of 

the regulator valve can prevent the evacuation system from being usable for evacuation.

Analysis of the condition has concluded that the regulator valve hangfire is caused by the 

Vespel piston coming into contact with the rod inside the regulator valve. This results from 

constriction of the piston inner diameter due to the stresses induced in the piston by the stored 

gas. Increasing the inner diameter (ID) of the piston will prevent this condition from occurring. 

As a secondary measure, a check of the piston ID is being added to the applicable maintenance 

documentation so that this critical dimension will be checked (and corrected, if necessary) at 

each valve overhaul.

The regulator valves used on the B737NG and MD-80/MD-90 evacuation slides listed in 

Table 1, above, are similar to the regulator valve used on the slide/rafts mentioned above. 

Although the risk of hangfire is less on B737NG and MD-80/MD-90 valves than on the slide/raft 

systems because the B737NG and MD-80/MD-90 valves use a lower stored gas pressure (3000 

psig as compared to 3290 psig on those slide/raft systems), the change to the Vespel piston ID 

is being applied to the B737NG and MD-80/MD-90 valves due to similarity of design.

(2) Scope of Action - This Service Bulletin is a complete and total measure. The units listed in 

Table 2, below, incorporate this modification at the time of manufacture and are not affected by 

this Service Bulletin.

Slide, Fwd Door, LH/RH

B737NG

5A3086-1, -3 and -301 B3F001 thru B3F611

Slide, Aft Door, LH/RH

B737NG

5A3088-1, -3 and -301 B3A001 thru B3A685

Slide, Fwd/Aft Door, LH/RH

B737NG

5A3307-1, -3, -5 and -301 BNG0001 thru BNG5707

Table 1. Unit Effectivity (Cont.)

NOMENCLATURE EVACUATION SYSTEM P/N AFFECTED UNIT S/N
Goodrich

SERVICE BULLETIN

25-349

Page 3 of 8

Orig. - Sep 15/04

Revision 1 - Jan 11/10

THIS DOCUMENT SUBJECT TO THE CONTROLS AND RESTRICTIONS ON THE FIRST PAGE. 

C. Description

This Service Bulletin describes a modification (reaming of the ID) to the Vespel piston in the regulator 

valves used on the affected units listed in Table 1, above, during a normal shop visit.

D. Compliance Recommendation

Goodrich recommends compliance with this Service Bulletin at the next scheduled shop visit of the 

affected unit.

E. Approval

This Service Bulletin has been reviewed by the Federal Aviation Administration (FAA) and the repairs 

and modifications described herein comply with the applicable Federal Aviation Regulations (FAR's) 

and are FAA approved.

F. Manpower

Goodrich estimates that this Service Bulletin action can be conducted in approximately 30 minutes 

(0.5 hours) during normal evacuation system maintenance. Goodrich will reimburse operators for 

labor expended in accomplishing this modification.

G. Materials

(1) Parts

(a) No new parts other than those normally replaced during overhaul are required to perform 

this Service Bulletin action.

(b) Replacing the Vespel piston with a new piston is an acceptable alternate means of 

compliance (Refer to Table 4, below, for part number information). Contact Aircraft Interior 

Products, Goodrich Corporation, Phoenix Arizona (V0ACH4) for a price quotation.

Table 2. Modification Effectivity 

NOMENCLATURE EVACUATION SYSTEM P/N AFFECTED UNIT S/N

Slide, Fwd Door, LH/RH

MD-80/MD-90

100504-205 D9F258 and Subsequent

Slide, Aft Service Door

MD-80/MD-90

100505-201 D9A123 and Subsequent

Slide, Tailcone

MD-80/MD-90

100506-201 and -203 D9T129 and Subsequent

Slide, Fwd/Aft Door, LH/RH

B737NG

5A3307-5 BNG5708 and Subsequent

NOTE: P/N 5A3086-( ) and 5A3088-( ) slides are no longer produced, so there is no new production 

effectivity for these models.
Goodrich

SERVICE BULLETIN

25-349

Page 4 of 8

Orig. - Sep 15/04

Revision 1 - Jan 11/10

THIS DOCUMENT SUBJECT TO THE CONTROLS AND RESTRICTIONS ON THE FIRST PAGE. 

(2) Materials - Normal evacuation system maintenance materials are required. Refer to the 

applicable Goodrich Component Maintenance Manual (reference Table 3, below) for this 

information.

H. Tooling

(1) To perform the check and reaming of the Vespel piston, a drill press, a "V" block, a 0.139 inch or 

a 3.53 mm diameter four flute high speed steel reamer, a hand deburring tool, and pin gauges 

are required.

(2) In addition, normal evacuation system maintenance tooling is required. Refer to the applicable 

Goodrich Component Maintenance Manual and Packing Instructions (reference Table 3, below) 

for this information.

I. Weight and Balance

Not affected.

J. Reference

The following Goodrich publications were used in the preparation of this Service Bulletin and should 

be referred to by maintenance personnel when performing these actions. 

K. Publications Affected

Goodrich Component Maintenance Manuals 25-60-34, 25-60-35 and 25-60-37 will require revision 

as a result of this Service Bulletin.

Table 3. Reference Publications 

DOCUMENT DESCRIPTION APPLICATION

25-60-33 Component Maintenance Manual (CMM) MD-80/MD-90 Slides

100504, 100505 and 100506 Series

25-60-34 CMM Reservoir Assembly

4A3699 Series

25-60-35 CMM Charged Cylinder Assemblies

4A3756 and 4A3904 Series

25-60-36 CMM B737NG Slides

5A3086 and 5A3088 Series

25-60-37 CMM B737NG Slide

5A3307 Series
Goodrich

SERVICE BULLETIN

25-349

Page 5 of 8

Orig. - Sep 15/04

Revision 1 - Jan 11/10

THIS DOCUMENT SUBJECT TO THE CONTROLS AND RESTRICTIONS ON THE FIRST PAGE. 

2. Accomplishment Instructions

WARNING: FOLLOW ALL WARNING AND CAUTION NOTES AND PROCEDURES IN THE 

APPLICABLE GOODRICH MAINTENANCE DOCUMENTS (REFERENCE PARAGRAPH 

1.J, ABOVE) WHEN PERFORMING THE FOLLOWING WORK PROCEDURES.

NOTE: The following instructions assume that the unit has been removed from the aircraft and is in 

the workshop.

• The following instructions outline the process for reaming the Vespel piston during a 

scheduled shop visit/overhaul of the affected unit. 

• Replacement of the Vespel piston with a new piston is an acceptable alternate means of 

compliance (Refer to Table 4, below, for part number information). In addition, operators may 

elect to pre-position new or previously modified Vespel pistons to form a rotable pool of pistons 

for accomplishing this modification in their fleet. 

• Goodrich can perform the reaming operation at the Goodrich Service Centers for operators 

that elect to outsource the reaming operation.

A. Unpack the evacuation system in accordance with the DISASSEMBLY section of the applicable 

Goodrich Component Maintenance Manual (CMM) (reference Table 3, above).

B. Remove the charged cylinder assembly in accordance with the applicable Goodrich CMM, 

DISASSEMBLY section.

C. Move the charged cylinder assembly to the valve shop.

D. Discharge the cylinder in accordance with Goodrich CMM 25-60-34 or 25-60-35, as applicable, 

DISASSEMBLY section.

E. Remove the regulator valve from the cylinder in accordance with Goodrich CMM 25-60-34 or 

25-60-35, as applicable, DISASSEMBLY section.

F. Disassemble the regulator valve in accordance with Goodrich CMM 25-60-34 or 25-60-35, as 

applicable, DISASSEMBLY section.

G. Clean and inspect the retained regulator valve components in accordance with Goodrich CMM 

25-60-34 or 25-60-35, as applicable, CLEANING and CHECK sections.
Goodrich

SERVICE BULLETIN

25-349

Page 6 of 8

Orig. - Sep 15/04

Revision 1 - Jan 11/10

THIS DOCUMENT SUBJECT TO THE CONTROLS AND RESTRICTIONS ON THE FIRST PAGE. 

H. Check and ream the Vespel piston as follows. See Figure 1.

(1) If necessary, allow the Vespel piston to come to room temperature.

(2) Use pin gauges and check the inner diameter (ID) of the Vespel piston.

(a) If the ID is greater than 0.139 inch (3.53 mm), discard and replace the Vespel piston. (Use 

P/N 3A3832-2 piston as the replacement part. When replacing P/N 3A3566-1 piston, a 

piston plug is also required to complete the assembly. See the Note following Table 4 for 

information about which piston plug to use.)

(3) Use a 0.139 inch or 3.53 mm diameter four flute high speed steel reamer in a drill press set at 

approximately 700 rpm. Use a "V" block to hold the Vespel piston with the conical end towards 

the reamer (see Figure 1). Feed the reamer at a slow steady speed to ream the ID of the Vespel 

piston.

CAUTION: TO PREVENT DAMAGE TO THE VESPEL PISTON/ROD SEAL SEALING 

SURFACES, USE CARE WHEN USING THE DEBURRING TOOL.

(4) Use a hand operated deburring tool to remove burrs from the edge of the reamed hole. See 

Figure 1.

(5) Remove any chips and clean the Vespel piston in accordance with Goodrich CMM 

25-60-34 or 25-60-35, as applicable, CLEANING section.

(6) Use pin gauges to verify that the ID of the Vespel piston is 0.137 - 0.139 inch (3.48 - 3.53 mm).

(7) Scribe "-2" on the base surface of the Vespel piston in the area of shown in Figure 1 to indicate 

that the piston has been modified.

Figure 1. 

Vespel Piston Reaming Dimensions
Goodrich

SERVICE BULLETIN

25-349

Page 7 of 8

Orig. - Sep 15/04

Revision 1 - Jan 11/10

THIS DOCUMENT SUBJECT TO THE CONTROLS AND RESTRICTIONS ON THE FIRST PAGE. 

I. Re-assemble the regulator valve in accordance with Goodrich CMM 25-60-34 or 25-60-35, as 

applicable, ASSEMBLY section.

J. If the regulator valve will receive an updated dash number (reference Table 4, below), cross out the

old valve dash number on the valve nameplate and stamp the new valve dash number.

K. For all regulator valves, use permanent ink and mark the valve body adjacent to the valve nameplate 

with the information "SB 25-349" to indicate compliance with this action.

L. Test the regulator valve in accordance with Goodrich CMM 25-60-34 or 25-60-35, as applicable, 

TESTING AND FAULT ISOLATION section.

M. Install the regulator valve on the cylinder and recharge in accordance with Goodrich CMM 

25-60-34 or 25-60-35, as applicable, ASSEMBLY section.

N. Mark the charged cylinder assembly as follows:

(1) For all units, stencil the information "SB 25-349" adjacent to the charged cylinder assembly part 

number to indicate compliance with this action.

O. Complete scheduled maintenance tasks on the unit, re-install the charged cylinder assembly and reclose the pack in accordance with ASSEMBLY section of the applicable Goodrich CMM or the 

applicable Goodrich Packing Instructions.

P. Mark the evacuation system as follows:

(1) For all units, permanently mark the girt adjacent to the system identification placard with the 

information "SB 25-349" to indicate compliance with this action.

Q. Record Service Bulletin compliance on the system information card.
Goodrich

SERVICE BULLETIN

25-349

Page 8 of 8

Orig. - Sep 15/04

Revision 1 - Jan 11/10

THIS DOCUMENT SUBJECT TO THE CONTROLS AND RESTRICTIONS ON THE FIRST PAGE. 

3. Materials and Identification

A. Parts

No new parts are required to perform this modification.

B. Identification

Component and system part numbers for specified end items and components are updated upon 

completion of these modifications. Block out the old dash number on the item and re-identify with the

post-Service Bulletin dash number as shown in Table 4, below. 

NOTE: * Vespel piston P/N 3A3832-2 requires a piston plug to complete the assembly. For regulator 

valve P/N's 4A3697-1, 4A3697-2, and 4A3698-1 used on MD-80/MD-90 slides, use Plug 

P/N 3A3833-1. For regulator valve P/N's 4A3865-2 and 4A3865-3 used on B737 slides, use Plug 

P/N 3A3833-1. For regulator valve P/N's 4A3865-4 and 4A3865-5 used on B737 slides, use Plug 

P/N 300382-1. For regulator valve P/N's 4A4047-2 and 4A4047-6 used on B737 slides, use Plug 

P/N 3A3833-1. (Plug P/N 300382-1 is an acceptable alternate to P/N 3A3833-1 on valve P/N's 

4A4047-2 and 4A4047-6 only.)

Table 4. Part Number Information 

DESCRIPTION PRE-SB PART 

NUMBER

POST-SB PART 

NUMBER

EQUIVALENT NEW 

PRODUCTION ITEM

Piston, Vespel 3A3566-1 3A3566-2 3A3832-2 *

Piston, Vespel 3A3832-1 3A3832-2 * 3A3832-2 *

Valve, Regulator 4A3865-4 4A3865-5 4A3865-5

Valve, Regulator 4A4047-2 4A4047-6 4A4047-6

Charged Cylinder Assy. 4A3904-3 4A3904-5 4A3904-5

Charged Cylinder Assy. 4A3904-4 4A3904-6 4A3904-6